In the processing of rotary cut wood veneer very often there arises the need for a differentiated, veneer cutting of the log in axial direction.
This may happen for example because of geometrical characteristics of the log such as excessive taper or because of local defects.
There are at present veneer cutting machines having an incising blade arranged in the middle to divide the rotary-cut veneer in two parallel strips sent to a reciprocating cutter with two twin blades side by side. Each blade has a width half the maximum width of rotary-cut veneer treated so as to be able to cut the respective strip produced by the incising blade. It is thus possible to perform independent cuts in the two strips and hence optimize the transverse cuts depending on the defects appearing separately on the two strips. Such a solution is however limiting add forces cutting with the incisor only in the middle of the veneer cutting machine. There is therefore prevented a choice of where to perform the incision depending on the characteristics of the rotary-cut veneer and the position of the defects. In various situations this translates into high wood scrap. Typical is for example the case of defects near the edges of the rotary-cut veneer.
There are also problems if it is desired to change over to production of whole rotary-cut veneer sheets. In this case indeed, either the cutter must be replaced with a whole blade or devices designed to accurately synchronise the two twin blades must be provided to obtain a single cut. The first solution involves high costs and shut down times of the plant often unacceptable. The second solution involves the employment of sophisticated and costly electronic or mechanical synchronising devices which are often not entirely reliable because of among other things the high cutting speeds required.
The general purpose of the present invention is to obviate the above shortcomings by supplying a flexible veneer cutting station permitting in a simple and effective manner division of the rotary-cut veneer sheet into parallel strips of any width and treatment of undivided rotary-cut veneer sheets.